Javascript AngularJS-设置默认下拉菜单选项时遇到问题

我对AngularJS是新手。目前，我在电子商务网站上应用了以下两个过滤器：

                         <div ng-show="user.ShipMethod != null && shippers && orderShipAddress.AddressName != 'BIG'" " ng-class="{'view-form-select': !currentOrder.LineItems[0].ShipperName, '': currentOrder.LineItems[0].ShipperName }">
                                <label ng-class="{required: !currentOrder.IsMultipleShip() && user.ShipMethod != null}" ng-show="currentOrder.LineItems[0].ShipperName || !currentOrder.IsMultipleShip() && user.ShipMethod != null">{{('Shipping' | r) + ' Method' | xlat}}</label>
                                <select class="form-control" ng-change="updateShipper()" name="shipMethod"
                                        ng-model="currentOrder.LineItems[0].ShipperName"
                                        ng-show="user.ShipMethod.ShipperSelectionType == 'UserDropDown'"
                                        ng-options="shipper.Name as (shipper.Name + ' ' + (shipper.ShippingRate.Price | currency | xlat)) for shipper in shippers | filter: { Name: '!Pick-Up at BIG'}"
                                        ng-required="!currentOrder.IsMultipleShip() && user.ShipMethod != null" >

                                    <option value=""></option>
                                </select>
                                <i class="fa fa-truck"></i>
                            </div>

                            <div ng-show="user.ShipMethod != null && shippers && orderShipAddress.AddressName == 'BIG'" ng-class="{'view-form-select': !currentOrder.LineItems[0].ShipperName, '': currentOrder.LineItems[0].ShipperName }">
                                <label ng-class="{required: !currentOrder.IsMultipleShip() && user.ShipMethod != null}" ng-show="currentOrder.LineItems[0].ShipperName || !currentOrder.IsMultipleShip() && user.ShipMethod != null">{{('Shipping' | r) + ' Method' | xlat}}</label>
                                <select class="form-control" ng-change="updateShipper()" name="shipMethod"
                                        ng-model="currentOrder.LineItems[0].ShipperName"
                                        ng-show="user.ShipMethod.ShipperSelectionType == 'UserDropDown'"
                                        ng-options="shipper.Name as (shipper.Name + ' ' + (shipper.ShippingRate.Price | currency | xlat)) for shipper in shippers | filter: { Name: 'Pick-Up at BIG'}"
                                        ng-required="!currentOrder.IsMultipleShip() && user.ShipMethod != null" >
                                    <option value=""></option>
                                </select>
                                <i class="fa fa-truck"></i>
                            </div>
                        </div>

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使用ng模型为列表项设置默认值。无论何时选择一个项目，您设置的ng模型变量都将更新

看

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使用ng模型为列表项设置默认值。无论何时选择一个项目，您设置的ng模型变量都将更新

看

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使用ng模型为列表项设置默认值。无论何时选择一个项目，您设置的ng模型变量都将更新

看

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使用ng模型为列表项设置默认值。无论何时选择一个项目，您设置的ng模型变量都将更新

看

我不清楚这个问题。是否要为列表项设置默认值？抱歉；是的…列表的默认值。我不清楚这个问题。是否要为列表项设置默认值？抱歉；是的…列表的默认值。我不清楚这个问题。是否要为列表项设置默认值？抱歉；是的…列表的默认值。我不清楚这个问题。是否要为列表项设置默认值？抱歉；是…列表的默认值。

$scope.currentOrder.LineItems[0].ShipperName = $scope.shippers[0];

<select  ng-options="p for p in animal"
            ng-model="selectedanimal"></select>